Details
| Original language | English |
|---|---|
| Pages (from-to) | 67-77 |
| Number of pages | 11 |
| Journal | Applied clay science |
| Volume | 28 |
| Issue number | 1-4 SPEC. ISS. |
| Publication status | Published - Jan 2005 |
Abstract
Pendimethalin (PM) is a dinitroaniline herbicide, highly hydrophobic and with a very low solubility in water. It is used for pre-emergence weed control, is usually applied before sowing, and mechanically incorporated into the soil. We tested sorption of PM on montmorillonite and on two different organo-montmorillonites in a mixed water-chloroform environment, to determine the feasibility of developing an environmentally oriented formulation of the herbicide. FTIR measurements show that the interactions of PM with montmorillonite on which difenzoquat (DZ) or mepiquat (MQ) were previously adsorbed are via the nitro and methyl groups of the herbicide. The pre-adsorbed organocations cause a dehydration of the interlayer space, leading to hydrophobicity of the organoclay. Changes in the electrokinetic surface charge of the organoclay, measured using a particle charge detector, confirm these results. The high affinity to PM and the hydrophobic behavior of the used organoclays were also demonstrated in experiments using a mixed chloroform-water environment. The crude clay mineral stayed in the water phase, whereas DZ- and MQ-montmorillonites concentrated in the PM-chloroform phase. Amounts of PM adsorbed to the organoclays using this method were very high (up to 0.65 mol PM kg-1 compound), which suggests a very efficient technology of preparation of herbicide-clay formulations, compared with techniques used in the past for similar herbicide-organoclay compounds. Plant experiments using the organoclay-herbicide formulation with higher amount of active ingredient (based on DZ-clay) demonstrate efficient herbicidal activity with 30% less active ingredient.
Keywords
- Adsorption, Clay, Difenzoquat, Electrokinetic surface charge, Hydrophobicity, Mepiquat, Montmorillonite, Organic cations, Pendimethalin
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geology
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
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In: Applied clay science, Vol. 28, No. 1-4 SPEC. ISS., 01.2005, p. 67-77.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Interactions of pendimethalin with organo-montmorillonite complexes
AU - Rytwo, Giora
AU - Gonen, Yotam
AU - Afuta, Shmuel
AU - Dultz, Stefan
N1 - Funding information: This research was supported in part by a Grant by the Niedersächsisches Ministerium für Wissenschaft und Kultur and by a fellowship by the Sacta-Rashi Foundation. We thank Prof. S. Nir for his useful comments and remarks.
PY - 2005/1
Y1 - 2005/1
N2 - Pendimethalin (PM) is a dinitroaniline herbicide, highly hydrophobic and with a very low solubility in water. It is used for pre-emergence weed control, is usually applied before sowing, and mechanically incorporated into the soil. We tested sorption of PM on montmorillonite and on two different organo-montmorillonites in a mixed water-chloroform environment, to determine the feasibility of developing an environmentally oriented formulation of the herbicide. FTIR measurements show that the interactions of PM with montmorillonite on which difenzoquat (DZ) or mepiquat (MQ) were previously adsorbed are via the nitro and methyl groups of the herbicide. The pre-adsorbed organocations cause a dehydration of the interlayer space, leading to hydrophobicity of the organoclay. Changes in the electrokinetic surface charge of the organoclay, measured using a particle charge detector, confirm these results. The high affinity to PM and the hydrophobic behavior of the used organoclays were also demonstrated in experiments using a mixed chloroform-water environment. The crude clay mineral stayed in the water phase, whereas DZ- and MQ-montmorillonites concentrated in the PM-chloroform phase. Amounts of PM adsorbed to the organoclays using this method were very high (up to 0.65 mol PM kg-1 compound), which suggests a very efficient technology of preparation of herbicide-clay formulations, compared with techniques used in the past for similar herbicide-organoclay compounds. Plant experiments using the organoclay-herbicide formulation with higher amount of active ingredient (based on DZ-clay) demonstrate efficient herbicidal activity with 30% less active ingredient.
AB - Pendimethalin (PM) is a dinitroaniline herbicide, highly hydrophobic and with a very low solubility in water. It is used for pre-emergence weed control, is usually applied before sowing, and mechanically incorporated into the soil. We tested sorption of PM on montmorillonite and on two different organo-montmorillonites in a mixed water-chloroform environment, to determine the feasibility of developing an environmentally oriented formulation of the herbicide. FTIR measurements show that the interactions of PM with montmorillonite on which difenzoquat (DZ) or mepiquat (MQ) were previously adsorbed are via the nitro and methyl groups of the herbicide. The pre-adsorbed organocations cause a dehydration of the interlayer space, leading to hydrophobicity of the organoclay. Changes in the electrokinetic surface charge of the organoclay, measured using a particle charge detector, confirm these results. The high affinity to PM and the hydrophobic behavior of the used organoclays were also demonstrated in experiments using a mixed chloroform-water environment. The crude clay mineral stayed in the water phase, whereas DZ- and MQ-montmorillonites concentrated in the PM-chloroform phase. Amounts of PM adsorbed to the organoclays using this method were very high (up to 0.65 mol PM kg-1 compound), which suggests a very efficient technology of preparation of herbicide-clay formulations, compared with techniques used in the past for similar herbicide-organoclay compounds. Plant experiments using the organoclay-herbicide formulation with higher amount of active ingredient (based on DZ-clay) demonstrate efficient herbicidal activity with 30% less active ingredient.
KW - Adsorption
KW - Clay
KW - Difenzoquat
KW - Electrokinetic surface charge
KW - Hydrophobicity
KW - Mepiquat
KW - Montmorillonite
KW - Organic cations
KW - Pendimethalin
UR - http://www.scopus.com/inward/record.url?scp=11044236267&partnerID=8YFLogxK
U2 - 10.1016/j.clay.2004.01.016
DO - 10.1016/j.clay.2004.01.016
M3 - Article
AN - SCOPUS:11044236267
VL - 28
SP - 67
EP - 77
JO - Applied clay science
JF - Applied clay science
SN - 0169-1317
IS - 1-4 SPEC. ISS.
ER -